Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 19 of 19 for “"mixed metal oxides"”.
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The low-temperature formation of mixed-metal oxides
This thesis describes a new route to lithium molybdate, Li₂MoO₄, which involves grinding together LiOH·H₂O and MoO₃ in air at room temperature. X-ray powder diffraction data show that the formation of highly crystalline Li₂MoO₄ is largely complete after 10 min, and that this product crystallises …
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Solvent-free Knoevenagel condensation over supported mixed metal oxides catalysts
Submitted in the fulfilment of the requirement for the Master's Degree in Chemistry, Durban University of Technology, Durban, South Africa, 2017.
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Structural and magnetic characterisation of some mixed metal oxides and oxyhalides
This thesis investigates the structural and physical effects of changing the ratio of Mn:Ga in the anion deficient perovskite, YSr\(_3\)Mn\(_{4-x}\)GaxO\(_{10.5}\). YSr\(_3\)Mn\(_{4-x}\)GaxO\(_{10.5}\) crystallises in the tetragonal space group I4/mmm, with lattice parameters a~7.64 Å and c~15.66 …
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Synthesis, Structure and Properties of Mixed Metal Oxides: From Pyrochlores to Fluorites
Introduction and Literature Review: Different families of oxide ion conductors and their applications are discussed. Experimental and Characterisation Methods: The synthetic methods and characterisation techniques used throughout this thesis are described. Synthesis, Structure and Transport …
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Aerosol Synthesis and Electrochemical Analysis of Niobium Mixed-Metal Oxides for the Ethanol Oxidation Reaction in Acid and Alkaline Electrolyte
… (EOR). The latter criterion is achievable in mixed-metal systems. Platinum is an effective metal for catalyzing surface reactions of many adsorbates and is usually implemented in the form of Pt nanoparticles supported on inexpensive carbon. This carbon is believed to be neutral in the …
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Preparation and characterisation of mixed CeO2-Nb2O5-Bi2O3 nanoparticles
Mixed metal oxides are ionic compounds containing at least two metal ions within an oxide structure. The literature contains a plethora of examples of mixed metal oxides on the bulk scale, which have been well characterised, however, mixed metal oxides on the nanoscale are far less well understood. …
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Metal oxide/organic interface investigations for photovoltaic devices
This thesis outlines investigations of metal oxide / organic interfaces in photo- voltaic devices. It focuses on device instabilities originating from the metal oxide layer surface sensitivity and it presents suggested mechanisms behind these in- stabilities. A simple sol-gel solution deposition …
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Intermetallic compounds by reductive annealing
… a new synthetic route to binary and ternary intermetallic compounds, which avoids the need for reaction at very high temperatures, multi-step reactions, reaction under vacuum and/or the synthesis of precursors. The route was adapted from a synthetic route reported for the synthesis of ternary and …
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Metal oxide electrocatalysts for alternative energy technologies
This dissertation focuses on the development of metal oxide electrocatalysts with varying applications for alternative energy technologies. Interest in utilizing clean, renewable and sustainable sources of energy for powering the planet in the future has received much attention. This will address …
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Advanced Spectroscopic Methods for Photochemical and Electrochemical Systems
… Electrocatalyst: Synergistic effects in cheaper Mixed-metal oxides (MMO) can overcome the traditional, expensive electrocatalysts, such as Pt/Pd/Ir. Here, we investigate a bifunctional MMO electrocatalyst composed of Cu, Co, and W for water splitting. The specific role of each metal element under …
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Enhanced Methane Oxidation Catalysis Through Feed Modulation And Oxygen Storage
… and optimization of novel Four-Way Catalysts – bimetallic Pt/Pd catalysts supported on Al2O3 and augmented by mixed-metal oxides, otherwise known as spinels. We initially demonstrate the enhancements resulting from the combination of spinels and modulating feed conditions. Next, we optimize …
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Getting to the Point: Bridging the Gap between Simple and Complex Catalytic Systems using Temporal Analysis of Products (TAP)
… under investigation are bulk transition metals: Pt), transition metals deposited on metal oxide supports: Pt/SiO<sub>2</sub>), and mixed metal oxides: VPO). The catalysts are applied to two types of reaction systems, CO oxidation and selective oxidation of hydrocarbons. The goal of the …
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Catalytic Conversion of Glycerol to Glycerol Carbonate Utilizing CO₂ and Dimethyl Carbonate
… XRD, TGA, SEM, and CO2-TPD techniques. Firstly, metal oxide catalysts of Al2O3, CaO, and MgO were used in the carbon dioxide and glycerol reaction. A glycerol conversion of 24.5±2.2 mol%, and glycerol carbonate yield of 12.8±1.2 mol% under optimized conditions of 5.5% catalyst loading, 150°C …
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High-throughput synthesis and characterization of vanadium mixed metal oxide pigments using synchroton radiation
UNA range of inorganic vanadium mixed metal oxides, with potential applications as<br/>inorganic pigments, have been synthesised and characterised in terms of their crystal<br/>structure, and band gap energies using powder X-ray diffraction (PXD), synchrotron-based<br/>X-ray absorption fine …
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Solid state NMR studies of oxide superconductors and related materials
… and magnetic properties of a variety of simple oxides, mixed metal oxides and oxide superconductors. Chapter 1 briefly reviews the basic theory of the NMR parameters of metals in the normal and superconducting state and the nuclear resonance properties of quadrupole nuclei. Chapter 2 introduces …
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Hyperbranched polyalkoxysiloxanes, synthesis, characterization and applications
… of different monomeric and polymeric alkoxymetallates like siloxanes and titanates. These polymers are used as precursors for ultrahydrophobic coatings and inorganic-organic composites of polypropylene and sulfonated polyetheretherketone. The properties of these materials in terms of …
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Design, Fabrication and Applications of Organic-Inorganic Hybrid Systems
… was used for the deposition of a variety of metal oxides/hydroxide nanoparticles. A classical surfactant free co-polymerization process was employed for the synthesis of these template particles. To facilitate the deposition of inorganic nanoparticles in subsequent steps, these colloidal …
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Optimizing Adsorption Energies of Reaction Products and Intermediates on Metal/Metal Oxide Catalysts to Achieve High Activity and Tunable Selectivity in Solid-Gas Phase Reactions
… the reaction to happen under milder condition. Metal catalysts supported on the metal oxide or unsupported metal crystallites have shown various catalytic behavior in different catalytic reactions. It can be divided into categories, catalysts with small sizes, such as single atoms, nanoclusters …
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Perovskites as New Support Materials for the Iron Based Fischer-Tropsch Synthesis
… active sites, etc.) [12]. Perovskites are mixed-metal oxides that have attracted much scientific attention due to their low price, adaptability and thermal stability. They generally have the formula ABO3 or A2BO4 (A and B are cations of different sizes, and O is the anion that binds them), …